A) Field of the Invention
The present invention concerns a process for contact-less temperature regulation, wherein the temperature is detected in a contact-less mode as an analog value with a temperature measuring device and digitized and wherein moreover there is provided a digital regulator which processes the detected temperature and which outputs a control signal which is dependent on predetermined parameters and the measured temperature.
B) History of the Prior Art
Corresponding processes and apparatus have already long been known. In that respect, the devices used for contact-less temperature measurement are generally pyrometers which, in dependence on the intensity and possibly also the spectrum of a received thermal radiation, generate an analog voltage or current signal. That signal is admittedly a measurement in respect of the measured temperature, but radiation intensity and spectrum are also influenced by other objects, including the measurement device itself, the temperature of which is not to be measured.
For correction purposes, it is possible to implement both purely mechanical measures, such as for example for the purposes of screening radiation, as well as to execute electronic corrections which correct the measurement signal which is detected in the form of an analog voltage.
Furthermore it is already known for the detected analog measurement signal to be digitized and subjected to further processing in digitized form, in particular therefore for example also to effect the necessary correction on the measurement signal so that the remaining signal actually forms a reliable reproducible measurement in respect of the actual temperature of an object whose temperature is to be regulated.
Contact-less temperature sensors such as for example pyrometers have in that respect the advantage that they in turn do not have any influence at all on the temperature of the object whose temperature is to be regulated, and that on the other hand they detect the temperature values extremely rapidly and correspondingly rapid reactions for temperature correction purposes are possible.
In the case of conventional temperature measurement devices with a digital electronic system, the electronic system admittedly also has digital outputs, but for the purposes of further processing and temperature regulation the digital signals are again converted into an analog signal and the analog signal is then again fed to an external regulator. If that regulator is a digital regulator, and the present invention assumes that to be the case, then the signal applied to an analog input of that digital regulator is now digitized again and, in dependence on predetermined regulating parameters, on the basis of those parameters and the freshly digitized and possibly already corrected temperature values, a control signal or a control value is provided at an output of the regulator, which is mostly an analog output. In the simplest case for example a voltage which is proportional to the measured temperature is produced at the output of the digital regulator, and in turn can be used to raise or lower the voltage or current feed to a heating element which heats the object in question, more specifically inversely proportionally to the control value produced or however proportionally to the inverted control value.
It will be appreciated that it is also possible to implement substantially more complicated regulating systems and non-linear regulating processes.
In the conventional systems, analog transmission of a signal which has already been previously digitized and converted again into an analog signal, from the electronic measurement system of the temperature measurement device to a digital regulator with an analog input, occurs in particular for the reason that the digital interfaces of regulators and temperature measurement devices are mostly suitable only for parameterization and process visualization, by virtue of their limited transmission speed. Particularly in the case of rapid changes in temperature and with the requirement for rapid regulating procedures, the regulating speed which is to be achieved in this way is not sufficient so that an analog signal is transmitted from the electronic measurement system to the regulator, in order to increase the transmission speed.
The present invention concerns an apparatus for contact-less temperature regulation comprising a suitable temperature measurement device which is accommodated in a housing, and a suitable electronic measurement system which operates at least in part digitally and which is also accommodated in the housing and which has an analog/digital converter for digitization of the analog measurement values and at least one analog output for further processing and use of an analog signal which is dependent on the measured temperature, and where the apparatus further has a digital regulator for producing a control value dependency on the measured temperature and predetermined parameters.
In the light of that state of the art, the object of the present invention is to provide a process and a corresponding apparatus for contact-less temperature regulation, which can have extremely short response times and which at the same time have a relatively high degree of accuracy and parameterizability.
In regard to the process as set forth in the opening part of this specification, that object is attained in that the data which are detected by the electronic measurement system and digitized for the first time are processed in one and the same processor for the purposes of temperature determination and regulation, which is integrated in the electronic measurement system or the housing of the electronic measurement system, so that the raw data are used within the processor both for ascertaining the current temperature and also for calculating and producing a control value, and thus the output of the electronic measurement system in the form of the regulator output directly provides a control value for influencing the temperature to be regulated of an object.
More particularly, the process of the invention includes the steps of detecting the temperature of the object using a contact-less temperature measurement unit that outputs an analog signal proportional to the temperature; digitizing the analog signal to obtain a digitized signal; processing the digitized signal in conjunction with predetermined regulating parameters within a digital regulator to obtain a temperature value; processing the temperature value using said digital processor within said digital regulator to obtain a control value; and outputting the control value to a means for regulating the temperature of the article.
In regard to the apparatus as set forth in the opening part of this specification the object of the invention is attained in that the digital regulator is integrated directly into the digital portion of the temperature measurement device so that the at least one analog output of the temperature measurement device is an analog output of the digital regulator.
Preferably, the temperature measurement device or the electronic measurement system also has a further analog output whose signal is a measurement in respect of the current temperature.
In that way, the favorable properties of digital regulators, more specifically a high level of accuracy, parameterizability, remote maintenance and remote diagnosis, are advantageously linked with the high-speed analog measurement process. By virtue of the elimination of additional digital-analog and analog-digital conversion steps, the regulator or the electronic measurement system has a shorter reaction time, while in addition there is an improvement in the level of accuracy of the detected temperature values which are used for the regulation procedure, so that the regulation procedure can also be implemented in a correspondingly more accurate fashion.
In particular however the operation of determining the current temperature takes place on or in the same microprocessor which also executes calculation of the control value on the basis of predeterminable parameters. It is possible in that way to drastically curtail the reaction time of the regulator as there is no need for any further conversion operations in respect of the data in digital/analog terms or any more conversion, and as all xe2x80x98on-chipxe2x80x99 procedures, because of the relatively short and optimized transit paths on the microprocessor, basically take place more rapidly than is possible with various interposed interfaces.